Safety device for elevators



L. COURTY.

SAFETY DEVICE FOR ELEVATORS. APPLICATION FILED SEPT, 23. 1919.

2 SHEEIS-SHEET 2.

WIT/{8858 L $221215 A 7TORNEY8 PATENT OFFICE.

LEON COURTY, OF WINDSOR, MISSOURI.

SAFETY DEVICE FOR ELEVATORS.

Application filed September 23, 1919.

To all whom it may concern:

Be it known that I, LEON Cormri a c1t1- zen of the United States, and a resident of Windsor, in the county of Henry and State of Missouri, have invented certain new and useful Improvements in Safety Devices for Elevators, of which the following 1s a spec1- fication.

My invention relates to lmprovements in safety devices for elevators.

An important object of my lnventlon is to provide an improved safety device for elevators in which the elevator Wlll be securely and positively locked to the guide rails when the supporting cable of the elevator breaks or does not serve to support the elevator whenever it is 1n danger of falling, irrespective of its position 1n the elevator shaft.

Another important object is to provide an improved safety device of simple and durable construction and in which the locking means will be so constructed, arranged and actuated as to be positive and reliable 1n operation.

Other objects and advantages reside in the certain novel features of the construction, arrangement and combination of parts and will become apparent as the descrlption proceeds, reference being bad to the accompanying drawings forming part of this specification and in WhlChE Figure 1 is a front elevat onal vlew of an elevator equipped with my improved safety device,

Fig. 2 is an elevational view of one slde of the elevator looking from the inside, parts being broken away for the sake of lllustration 3 is an elevational view of the same side but taken from the outside of the elevator, parts being broken away for the sake of illustration.

Referring to the drawlngs my invention includes an elevator of any conventional type shown for the sake of illustration as including a platform frame A having a platform or floor B secured to the top thereof and provided with lift rods C secured thereto and having their upper ends terminating in eyes C which are adapted to be engaged withsupportlng connectlons D of the supporting cable D. Guide rails E of conventional construction cooperate with Specification of Letters Patent.

Patented May 25, 1920.

Serial No. 325,720.

elevator guides F which are mounted on the elevator in a manner to be hereinafter more fully described.

A pair of standards 10, preferably of metallic material are arranged 011 each side of the elevator and are secured adjacent their lower ends to the rectangular frame A of the elevator platform. The standards of each pair are spaced from each other and each of the standards of one pair are connected at their upper ends by cross bars 11 to the corresponding standards of the other pair. These cross bars 11 are secured to the standards by having vportions 11 at each of their ends bent at right angles and bolted to the standards as shown in the drawings. It is obvious that the standards being spaced the cross bars are also spaced.

A vertically reciprocating slide 12 is ar ranged between the standards 10 and is prevented from outward displacement by fiattened bars 13 bolted to the outside of said standards and extending across the space between the standards. Adjacent the upper and lower ends of the standards and extending transversely to the outside thereof and secured thereto are plates 14. These plates and the standards are provided with alined hearings in which are journaled operating rock shafts 15. As shown these hearings and rock shafts are preferably four in number. The rock shafts extend entirely across the elevator and through the standards and have fixed to each of their outer ends locking dogs 16 adapted to be engaged with the guide rails of the elevator in a manner to be hereinafter more fully described.

As shown in the drawings these rock shafts are arranged in pairs, one pair arranged at the upper end of the elevator structure and the other pair at the lower end thereof and the shafts of each pair are arranged on opposite sides of the elevator guide rails. In this manner the locking dogs carried by the upper and lower shafts on one side of the guide rail bite into or engage the face thereof at points directly opposite to the points at which the locking dogs of the upper and lower shafts on the other side engage the opposite face thereof. The points at which the locking dogs engage the guide rails are immediately adjacent the elevator guides F which are secured to the standard as" shown.

Adjacent the inner side of the standards 10 the rock shafts are provided with radial arms 17 which are suitably recessed and bored to be pivotally connected to links 18 which in turn have their outer ends pivotally connected to offset portions 19 of connecting rods 19. These connecting rods are secured in any suitable manner by bolts or nuts or otherwise to the slides 12.

Each of the slides 12 is provided with a lug 12 which extends inwardly therefrom at right angles thereto between the spaced cross bars 11. A three-arm rock lever 20 is mounted for oscillating motion on a transverse shaft 21 extending between the cross bars 11. As shown in Fig. 1 there are two of these three-arm rock levers, one arranged adjacent each of the slides 12. Each of these levers has an inner and downwardly curved arm adapted to be engaged with the end of the retractile spring 22, an outer and upwardly curved arm adapted to be engaged with the lug 12' of the slide and an upwardly extending arm adapted to be engaged by the auxiliary connections 23 of the supporting cable D.

In operation the elevator is supported by the supporting cable D, the lift thereof being transmitted through the supporting connections and the lift rods to the platform. While the supporting cable is exerting. its normal or lifting force the auxiliary connections 23 have rotated the rock levers 20 against the action of the retractile spring 22 to lift the slides 12 and attached connecting rods vertically and thereby through the medium of links 18, and radial arms 17 cause the locked shafts 15 to rotate to swing the locking dogs out of engagement with the elevator guard rails E. When the elevator is falling or in danger of falling by reason of the supporting cable D breaking or not serving to support the elevator, or for other reasons the auxiliary connections slacken and no longer serve to maintain the upward extending arms of the rock lever in raised position. The retractile spring 22 then acts to reversely rotate the rock levers and move the slides, connecting rods, eta, vertically downward to rotate the shaft 15 in such direction as to force the locking dogs into positive engagement with the guide rails E. Any tendency for the elevator to fall will only serve to more tightly bind the locking dogs in locking engagement increasing in proportion to the tendency to fall. In this manner the elevator is securely locked in position and will only be released upon the supporting ca le resuming its supporting functions. It is to be noted that the stresses incident to the locking action are evenly distributed throughout the elevator structure, due to the arrangement of the locking dogs and their simultaneous action effected as previously set forth. Moreover the locking action is complete, positive and effective irrespective of the load carried, or the distribution of this load on the platform.

I claim:

1. A safety device for elevators comprising the combination with an elevator platform, a lifting cable therefor, elevator guides associated with said platform and guide rails cooperating therewith, of spaced standards secured to each side of the elevator platform, spaced cross bars connecting said standards, a vertically movable slide arranged between each pair of standards, rock shafts journaled in each of said standards adjacent their upper and lower ends, locking dogs fixed to the outer ends of said rock shafts and adapted to be engaged with the elevator guide rails, 'adial arms secured to said rock shafts, a connecting rod fixed to each of said slides, links connecting said radial arms and said connecting rods, a three-arm rock lever arranged between said spaced cross bars having one arm thereof engaged with said slides, a retractile spring engaging another arm of said lever and auxiliary connections from said supporting cable engaged with the other arm of said lever as and for the purpose set forth.

2. A safety device for elevators comprising the combination with an elevator plat form, a lifting cable therefor, elevator guides associated with said platform and guide rails cooperating therewith, of a pair of standards secured to each side of of the elevator platform, a vertically movable slide arranged between each pair of standards, rock shafts journaled in each of said standards adjacent their upper and lower ends, locking dogs fixed to the outer ends of said rock shafts and adapted to be engaged with the elevator guide rails, radial arms secured to said rock shafts, a connecting rod fixed to each of said slides, links connecting said radial arms and said connecting rods, a three-arm rock lever arranged between said spaced cross bars having one arm thereof engaged with said slides, a retractile spring engaging another arm of said lever and auxiliary connections from said supporting cable engaged with the other arm of said lever as and for the purpose set forth.

3. A safety device for elevators comprising the combination with an elevator platform, a lifting cable therefor, elevator guides associated with said platform and guide rails cooperating therewith, of rock shafts, locking dogs fixed to said rock shafts and adapted to be engaged with said guide rails, means connecting said rock shafts and adapted to simultaneously move same to locking or release position, a three-arm rock lever having one arm engaged with said means, a retractile spring engaging another arm of said lever and auxiliary connections from said supporting cable engaged with the other arm of said lever all as and for the purpose set forth.

4. A safety device for elevators comprising the combination with an elevator platform, a lifting cable therefor, elevator guides associated with said platform, and guide rails cooperating therewith, of a pair of rock shafts arran ed at the upper and lower ends of said e evator structure, the shafts of each pair being disposed on opposite sides of the elevator ide rails, looking dogs fixed to said sha ts and adapted to be engaged with said guide rails, a vertical slide connected with said rock shafts, a vertically swinging lever connected with said slide, the axis of said lever being disposed at right angles to the axes of said rock shafts, a retractile spring engageable with said lever and an auxiliary connection from said lifting cable engageable with said lever, all as and for the purposes set forth.

5. A safety device for elevators comprising the combination with an elevator platform, a lifting cable therefor, elevator guides associated with said platform and guide rails cooperating therewith, of spaced standards secured to each side of "said elevator platform, spaced cross bars connecting said standards, a pair of rock shafts arranged at the upper and lower ends of said elevator structure, the shafts of each pair being journaled in said standards on opposite sides of the elevator guide rails, looking dogs fixed to said rock shafts and adapted to be engaged with said guide rails, a vertical slide arranged between each pair of spaced standards and connected with said rock shaft, a pair of vertically swinging levers journaled in said cross bars, a retractile spring arranged between said cross bars and having its ends engaged each with one of said levers, and auxiliary connections from said lifting cable engageable with said levers, all as and for the purposes set forth.

LEON COURTY. 

